1. Field of the Invention
The present invention relates generally to making up and breaking out well bore tubular and, more particularly, to apparatus and methods for a makeup and break out tool that is readily maneuverable in a rig floor environment.
2. Description of the Background
Makeup and break out tools are used to spin, makeup, and break out well bore tubular that may have a wide range of diameters. It has been found by oil companies that separate, manually operated tongs, spinners, and/or chains are often significantly slower in making up and breaking out well bore tubular than a single tool or unit that does all such functions. The speed advantages of a single unit include factors such as eliminating the need to redress tongs when changing from drill pipe to collars and the integration of spinning with makeup and break out functions. Due to the high daily cost of drilling rigs, the time savings can be substantial. Comparison studies between use of traditional separate tongs and spinners as compared with a single unit makeup and break out tool have shown cost savings that may range from one-quarter of a million to more than a million dollars per well. Another time saving advantage is that a self-contained unit can be used to make up or break out pipes at difficult positions in the rig or derrick - a feature that can save a great amount of time especially in certain situations that occasionally occur, e.g., stuck pipe. Furthermore, when desired, pipes can be readily made up or broken out while in the mousehole with the rig otherwise occupied. An exemplary self-contained unit for making and breaking joints in pipe strings is shown in U.S. Pat. No. 5,868,045 and U.S. Pat. No. 5,386,746 which are incorporated herein by reference.
The self-contained system operates more reliably than separate tongs and spinners by providing a central torque regulator that connects to and controls all components to assure consistent makeup. This feature prevents thread damage caused by over tightening and automatically prevents errors that could result in under-torqued connections.
The system eliminates accident conditions associated with separate independent tongs readily exposed on the floor, and the attendant separate cables used to pull on each separate tong, and use of snatch blocks. Safety is also improved because providing a single tool to perform all such functions rather than separate elements permits the use of central safety features such as, for instance, a lockout to prevent spinner operation if the tongs are not engaged, a safe location for the operator to stand and work, a design whereby the operator""s hands and feet are safely away from moving parts, elimination of spinning chains, and a lockout to prevent operation of the lift cylinder when any tong is engaged.
Because of the great utility of a self-contained unit to makeup and break out pipes, it has been found desirable to make further improvements. For instance, a support line is normally secured to the top of the unit to support the unit and permit mobility of the unit. Even though the unit actually requires only one line as compared to at least two support lines used to support separate tongs as well as pull lines for pulling on each separate tong, it would nonetheless be desirable to eliminate the support line on some rigs due to limited line availability. Moreover, because a self-contained unit will necessarily have considerable weight, effort is required, usually involving two people, to initially pull the makeup and break out unit to the desired connection. While even these factors are at least on a par or typically better than use of separate tongs and spinners which require at least two support lines and two pull lines and at least two or three people to operate the tongs and pull lines, nonetheless it would be desirable to control a makeup and break out unit with a single operator using automated controls without the need for any lines.
One commercially available system uses two straight tracks wherein motored wheels move the make-up and break-out tool forward and backward. However, this configuration uses rig floor space at all times, may not be used elsewhere on the rig floor, is very limited in operational positioning, and may be difficult to adapt to many rig floor arrangements.
Consequently, there remains a need for a self-contained makeup and break out unit that permits a single operator to perform the function of making and breaking the joints of well bore tubular. It would also be desirable to eliminate the requirement for a support line. However, it would be desirable to maintain the ability to use a line to permit the unit to be used in odd locations when desired and/or for transport purposes. Those skilled in the art have long sought and will appreciate the present invention which provides solutions to these and other problems.
The present invention was designed to provide more efficient operation to thereby reduce drilling costs, improve reliability of making and breaking pipe joints, permit increased automation to reduce required manpower, improve safety, and to free other rig equipment for other uses.
Therefore, it is an object of the present invention to provide an improved self-contained unit for making and breaking well bore tubular.
Another object of the present invention is to automate most of the functions of making and breaking of pipe joints for more efficient operation.
Yet another object of the present invention is to provide a means for powered 3-dimensional movement of a self-contained pipe making and breaking unit.
Yet another object of the present invention is to free up equipment on a rig such as support lines.
An advantage of the present invention is improved rig safety.
Another advantage of the present invention is faster operation.
Yet another advantage is improved reliability and consistency in making up joints.
These and other objects, features, and advantages of the present invention will become apparent from the drawings, the descriptions given herein, and the appended claims.
Therefore, the present invention provides for a maneuverable powerjaw apparatus for making and breaking joints of well bore tubular which comprises at least two powered torque arms for applying torque to the joints of the well bore tubular. A support member supports the powered torque arms. A mobile frame supports the support member and the two powered torque arms. The support member is preferably movable with respect to the mobile frame. One or more hydraulically movable members are mounted between the support member and the mobile frame. One or more wheels are mounted to the mobile frame.
A first wheel and a second wheel are mounted to the mobile frame with a fixed orientation. A first hydraulic control motor may be used to activate the first wheel, and a second hydraulic control motor may be used to activate the second wheel. Preferably, the two wheels are mounted to the mobile frame such that a straight line passes through each of the two wheels and a respective of the well bore tubular when the at least two power torque arms apply the torque.
In other words, a maneuverable power jaw apparatus is provided for making and breaking joints of well bore tubular such that the maneuverable power jaw apparatus may be operable on a rig floor. A mobile frame supports a support member to which at least two powered torque arms are attached. At least three wheels are mounted to the mobile frame to permit movement of the mobile frame on the rig floor. At least one movable member is mounted to the mobile frame and the support member for affecting movement between the mobile frame and the support member. Preferably the movable member comprises a hydraulic rod for vertically moving the support member with respect to the mobile frame.
In operation, a method is provided for a power jaw apparatus for making and breaking joints of well bore tubular which includes mounting the power torque arms in a housing and steering the housing in a left-hand direction or right-hand direction on the rig floor. Preferably, steering is accomplished by activating a hydraulic motor. Moreover, by controlling power applied to two wheels with a fixed orientation steering may be affected because the wheels are preferably positioned in a reverse tricycle orientation. At least one wheel, at the rear of the housing, has a rotatable orientation and follows movement controlled by the two front wheels. The powered torque arms are preferably hydraulically lifted for vertical engagement with a respective of the joints. Preferably wheel guards are provided on the housing around the plurality of wheels.